Organic electroluminescent display board and method for packing thereof
The present invention relates to organic electroluminescent (EL) display panel, more particularly relate to the method for OLED panel and encapsulation thereof.
Recently, along with the size of display device increases day by day, the demand of the flat-panel screens that occupies little space is increased gradually.As an example of flat-panel screens, the EL display receives much concern.
The EL display is made material by it can be divided into inorganic EL display and OLED display.Wherein, when the electronics that is injected into organic EL layer combines and is eliminated with the hole, OLED display emits beam.Organic EL layer is between negative electrode and anode.
The advantage of OLED display is that its driving voltage is than low (for example, about 10V or lower) of plasma display panel (PDP) or inorganic EL display.And because OLED display also has other advantage, therefore for example wide visual angle, high speed reactivity and high-contrast can be used as the pixel of graphic alphanumeric display, television video display and surface source of light.Further, because OLED display thin thickness, in light weight, and good color sensitivity is arranged, therefore be suitable for as flat-panel screens of future generation.
But the serious problems of OLED display are that its life-span is short for commercial applications.
The life-span of display is determined by multiple factor, for example the oxidation of the impurity in the organic substance, organic substance and interelectrode interface, low organic substance crystallization temperature (Tg) and the display that caused by oxygen and moisture.The problem relevant with these factors can have the material of high crystallization temperature and the interface between electrode and organic substance by refining organic substance, exploitation and introduce organic metal and solve.But the relevant problem of oxidation that solves the display that is caused by oxygen and moisture is difficult.
The oxygen of oxidation display and moisture can exist in the display, perhaps can be infiltrated by the outside in each stage of manufacture process.Oxygen and moisture infiltrate in the aperture of display and oxidation organic membrane and metal, thereby the lighting function of display was lost efficacy.
In relevant technology, be head it off, display is covered with shield glass, to cut off moisture and oxygen from the outside.
In other words, shown in Fig. 1 a and 1b, the OLED display that glass plate 1, first electrode 2, organic EL layer 3 and second electrode 4 are housed is covered by shield glass 5, to cut off moisture and oxygen.
Shield glass 5 is combined on the angle of plate by binding agent 6.
But,, throw off on binding agent 6 slave plates after after a while because the adhesion strength of binding agent 6 is not high for glass plate.
If throw off on binding agent 6 slave plates, will between plate and binding agent, form the slit, so moisture and oxygen penetrate into display.Owing to these reasons, the problem that display life shortens has appearred.
For overcoming the above problems, the purpose of this invention is to provide a kind of OLED panel and method for packing thereof, wherein by improving the life-span of the adhesion strength prolongation display between plate and binding agent.
For reaching above purpose, in having the OLED panel of sandwich construction, wherein on transparent panel, form first electrode and second electrode, and form one deck organic EL layer between the two at least, OLED panel of the present invention is included in the resilient coating that forms on the transparent panel and is positioned at screening cover on the resilient coating.
On the other hand, have in the method for OLED panel of sandwich construction in encapsulation, wherein on transparent panel, form first electrode and second electrode, and between the two, form one deck organic EL layer at least, the step that the present invention encapsulates the method for OLED panel comprises: form resilient coating on transparent panel, and screening cover is placed on the resilient coating.
Resilient coating is formed on the connector engages district of first, second electrode and the whole plate surface the pixel region, perhaps only be formed on screening cover and be positioned at zone on the transparent panel, perhaps the residing zone of screening cover on residing zone of screening cover onboard and the electrode all forms resilient coating.
And the resilient coating in screening cover zone of living in has irregularly shaped or point-like.The point-like resilient coating can be any shape in circle, triangle, quadrangle, the polygon etc.
Resilient coating outside the resilient coating in screening cover zone of living in and the screening cover zone of living in is commaterial or different materials.In other words, the material that the resilient coating in screening cover zone of living in comprises is silica or silicon nitride, and the material that the resilient coating outside the screening cover zone of living in comprises is silica, silicon nitride, polyimides or polypropylene.
Among the present invention, the zone of living in of screening cover onboard forms inorganic material, as silica or silicon nitride, with the adhesion strength between reinforcement plate and binding agent, prevents that outside moisture and oxygen from infiltrating in the plate, thereby prolongs the life-span of display.
It should be understood that above-mentioned general description and following detailed description all are as an illustration and explain, are intended to provide the further explanation to claim of the present invention.
Also in conjunction with the detailed description to embodiment, other purpose of the present invention, feature and advantage will be clearer with reference to the accompanying drawings.In the accompanying drawings:
Fig. 1 a and 1b are the plane graph and the profiles of the encapsulation OLED panel method of prior art;
Fig. 2 a and 2b are plane graph and the profiles according to first embodiment of the invention encapsulation OLED panel method;
Fig. 3 shows the various irregularly shaped of resilient coating among Fig. 2 a;
Fig. 4 a and 4b are plane graph and the profiles according to second embodiment of the invention encapsulation OLED panel method;
Fig. 5 a and 5b are plane graph and the profiles according to third embodiment of the invention encapsulation OLED panel method.
Describe the preferred embodiment of OLED panel of the present invention and method for packing thereof below with reference to the accompanying drawings in detail.
Fig. 2 a and 2b are plane graph and the profiles according to first embodiment of the invention encapsulation OLED panel method.
Shown in Fig. 2 a and 2b,, go up formation transparent conductive film, for example indium tin oxide (ITO) at transparent insulation plate 11 (for example glass) for forming OLED display.The pattern that uses photoetching process to obtain transparent conductive film has a plurality of bands and contacts pin 12-1 to form first electrode, 12, the first electrodes, is used for contacting with second electrode that forms later on.
Except the connector engages district of first electrode 12 with pixel region and contact the pin 12-1, form resilient coating 13 on the surface of whole plate.
Form the difference of position, the effect difference of resilient coating according to it.In other words, it is different with the resilient coating around the pixel region to be positioned at the function of the resilient coating on 11 jiaos of the plates.
The effect that is positioned at the resilient coating on 11 jiaos of the plates is when adding a screening cover to plate, to strengthen the adhesion strength of binding agent.The effect of the resilient coating around the pixel region is to play insulating effect each other between first electrode and second electrode and at second electrode.
The resilient coating zone (being the residing zone of screening cover) that is formed on 11 jiaos of the plates can be irregularly shaped or point-like, as shown in Figure 3, and to strengthen the adhesion strength of binding agent.
That is to say that the point-like resilient coating can be a different shape, as any shape in circle, triangle, quadrangle and the polygon.
Resilient coating around the pixel region can be a ribbon, and its direction is perpendicular to first electrode 12.As mentioned above, since the effect of resilient coating 13 according to the difference of its residing position and therefore difference can use a kind of material or different materials to be used as resilient coating 13.
In other words, the material of resilient coating on the plate angle (being the resilient coating in screening cover zone of living in) is an inorganic matter, as silica and silicon nitride.The material of the resilient coating (being the resilient coating outside the screening cover zone of living in) around the pixel region can be an inorganic material, as silica and silicon nitride, or organic substance, as polyimides and polypropylene.
At this moment, the thickness of resilient coating is about 0.1~5 μ m.
Then, in order to form electric insulation between the second electrode band that will form afterwards, on resilient coating 13, form electric insulation barrier band 14.
Subsequently, on electric insulation barrier band 14, form organic EL layer 15.
The width that organic EL layer 15 forms is wideer than whole luminous zone (the whole zone of first electrode and the second electrode square crossing).But organic EL layer 15 should be formed on the inboard of contact pin 12-1 end.
Use electric conducting material again, as Al, Mg:Ag, Al:Li forms second electrode 16.Like this, OLED display completes.
Here, second electrode 16 is should be than the luminous zone wide and be connected with contact pin 12-1.
Subsequently, covering screening cover 17 on the OLED display, to cut off moisture and oxygen.Use binding agent 18 that screening cover 17 is attached on the resilient coating 13 on the plate angle.A kind of UV sclerosis polymer substance is as binding agent 18.In addition, also can use other binding agent, as thermo-hardening binder or inorganic binder.
After forming resilient coating as mentioned above,, just strengthened the adhesion strength of binding agent, thereby outside moisture or oxygen can not enter in the OLED display if screening cover is attached on the resilient coating with binding agent.
Fig. 4 a and 4b are the plane graph and the profiles of second embodiment of the invention encapsulation OLED panel method.
In the second embodiment of the present invention, only the zone of living in of screening cover onboard forms resilient coating.
Usually, because the adhesion strength between encapsulation binding agent and the plate is not high, therefore only onboard screening cover zone of living in forms resilient coating.
And resilient coating can be irregular shape or point-like, and to strengthen the adhesion strength of binding agent, its mode is identical with first embodiment.
In a second embodiment, because only the zone of living in of screening cover onboard forms resilient coating, therefore simplified technology.But in this case, what need is not need the display structure of electric insulation barrier or utilize the electric insulation barrier that does not only have resilient coating to make the display structure of electric insulation between second electrode.
Fig. 5 a and 5b are plane graph and the profiles according to third embodiment of the invention encapsulation OLED panel method.
In the third embodiment of the present invention, resilient coating is all arranged in the residing zone of screening cover of residing zone of the screening cover of plate and electrode.
And resilient coating can have irregular shape or point-like, and to strengthen the adhesion strength of binding agent, its mode is identical with first embodiment.
In the 3rd embodiment, technology has also been simplified.But what need is not need the display structure of electric insulation barrier or utilize the electric insulation barrier that does not only have resilient coating to make the display structure of electric insulation between second electrode.
As mentioned above, OLED panel of the present invention and method for packing thereof have following advantage:
Have inorganic matter in the residing zone of the screening cover of plate,, make that the adhesion strength between plate and the binding agent has strengthened as silica and silicon nitride.This has prevented that outside moisture and oxygen from entering into plate, thereby has prolonged the life-span of display.
For those of ordinary skills, to describing the modifications and variations done more than the present invention all within spirit of the present invention, and do not depart from technology connotation of the present invention.But technical scope of the present invention is not confined to the description of the foregoing description, but is determined by claim.